Fetal brain implants improve maze performance in hippocampal-lesioned rats.

Hippocampal tissue from day 16 fetal rats was implanted into the damaged hippocampal formation of adults. Significant recovery of the lesion-induced deficit in spatial maze performance was observed, particularly in those animals which showed integration of the implanted fetal tissue with the host hippocampal formation. A two-stage procedure in which 2 weeks or more elapsed between the initial lesion and the implantation resulted in more successful tissue integration and better behavioral recovery.